Ichthyological and limnological observations on the Sali river basin (Tucumán, Argentina)

Abstract

The ichthyofauna of the Sali river basin, Tucuman, Central Argentina is analyzed. Twenty three species and two subspecies were collected, of which nine species and one subspecies are new for the Sali river basin: Cheirodon interruptus, Odontostilbe microcephala, Cyphocharax cf. modestus, Jobertina rachowi, Pimelodus albicans, Trichomycterus alterum, Corydoras paleatus, Jenynsia lineata alternimaculata, Bujurquina vittata and Cichlasoma portalegrense. This represents a 37% increase in the known diversity of the Sali river fish fauna. The Paranensean composition of this fauna lends support for a western extension of the Parano-platense zoogeographic province. The hypothesis is advanced that the lack of tributaries and therefore the lack of environments of creek type in the Dulce river explains the observed impoverishment in the number of species compared with the Sali. Physicochemical data obtained at ten localities show that the mean pH is higher in the Sali river than in the upper Parana and Paraguay rivers, but is nearly the same as that in Cordoba environments. Total dissolved solids are less than in Pampean lakes or Cordoba creeks. At all localities in the Sali river C03 H-, Ca2+ and Na+ were the most abundant ions.